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Abstract
A perfect smile is the objective of esthetics in dentistry, and the color of the teeth is of particular cosmetic importance. The best conservative treatment for discolored teeth is bleaching. One of the most effective bleaching agents is hydrogen peroxide, whose application in dentistry was described as early as 1884. Bleaching can be performed internally on non-vital teeth or externally on vital teeth.
Recently newer techniques using vital bleaching agents (hydrogen peroxide, carbamide peroxide and sodium perborate) have been advocated to eliminate the effect of such stains. These techniques utilize plasma liquid, laser, super sonic system and at home tooth whitening systems (over the counter method). The different bleaching procedures have grown the hopes of satisfying the patient’s demands for a white smile yet there is still controversy in the literature as to whether these bleaching agents and techniques could adversely affect the dental hard structure.
The use of bleaching materials on dental hard structure may cause increased porosity, roughness non-uniform changes and morphological alteration of the enamel surface that could result in tooth sensitivity especially after vital bleaching techniques. Therefore, throwing more light regarding bleaching materials and procedures and their effect on tooth hard structure is recommended to eliminate the drawbacks of their use. Furthermore, the hypothesis that the new concept of remineralization could retain the calcium and phosphorus levels in tooth structure is warranted.